The state of manicuring and trimming around trees, plants and other grounds has significantly changed over the last ten to fifteen years. The advent of low cost, lightweight flexible line trimmers, both gas and electric powered, has made it possible for many property owners to acquire an effective trimming tool. Yet, in the hands of an unskilled or unknowledgeable person, use of these same effective tools can have disastrous results, killing plants and trees, and damaging other objects where trimming is attempted. For example, when trimming around trees, it is easy to get too close and contact the trunk with the flailing line. This destroys the bark, and may even girdle the tree, killing it.
Trimming too closely to other objects, such as siding, posts, grave markers and the like can also damage them. Mowing too closely to trees and plants also may harm them, particularly when the mower strikes a tree, for example, and destroys its bark.
In order to beautify grounds, natural mulching systems, such as natural bark, wood products, peat, etc. have been used to mulch around trees, plants and other items. These inhibit weed and grass growth and present a manicured appearance, but require continual care and replenishment. The initial preparation and continuing care are expensive and many trees go initially unprotected, or the mulch is not maintained, either situation leaving them subject to trimming or mowing damage when grass or weeds grow near them.
In considering use of mulching systems particularly around trees and plants, it is thus important to inhibit near weed and grass growth to eliminate the need for close-in trimming and mowing, but at the same time to protect and accommodate the underlying root system, and to present a desired aesthetic appearance. It does little good to inhibit grass and weed growth with a mulch system which has a damaging effect on the underlying root system, killing the very tree it is designed to protect. Mulch systems which fail to transmit air and water to such root systems, or which act to draw water away from such systems, do more harm than good.
Natural mulching systems having numerous advantages and have been used for some time; they usually provide a highly desirable, natural appearance. Nevertheless, they also present several inherent drawbacks including the aforementioned expense and maintenance requirements. For example, they must be periodically replenished due to both natural and mechanical degradation. For example, hard rains, winds and even watering may flush away the mulch, leaving the ground and root system thereunder subject to erosion from water force and other environmental conditions.
Certain natural mulch systems may also tend to hold water themselves, not passing it to the underlying roots, or actually draining it away from the roots by capillary action.
It has thus been one objective of this invention to provide improved mulching systems and components.
A further objective has been to provide a mulch system having a natural mulching appearance and preventing weed and grass growth around trees while passing moisture and air through to the root system, and insulating such root system.
To these ends, the invention contemplates the combination of a waste product with other components in a mulching system for satisfying these objectives while at the same time providing a waste product usage having a significant beneficial impact on our existing environment.
More particularly, in a preferred embodiment of the invention, rubber and fibers are ground from used automobile tires, and are combined with a curable binder to form a matrix defining a moisture and air porous, weed and grass-growth preventive pad. An aperture is disposed in the center of the pad to accommodate a tree trunk, and a slit is preferably partially formed or cut from a circumference of the pad to the aperture.
In use, the pad is torn along the partially cut slit to provide a jagged seam so that the pad can be disposed around a tree trunk. Thereafter, the jagged, seam edges are rejoined to provide a trunk-surrounding pad, and the seam is virtually, if not totally, obscured, all to provide a naturally mulched appearance.
In another embodiment of the invention, a curable, liquid binder is mixed with the rubber granules and fibers. This mix is packaged in containers from which the mulch can be poured in place. Upon curing, a porous weed and grass growth preventing pad is formed in place. Such pourable mulch system can be used alone, or small packets thereof used with the first embodiment of a cured pad to fill in around the center trunk hole, or to adhere the slit or seam.
In producing functionally useful pads, it is also desirable that they have a natural aesthetic appearance, as if the pad was indigenous organic mulch. But rubber tire particles are coal black, while the binder coating them is clear, or may be yellowish in appearance. Frequently, such binder/granule mix, when cured, may have an undesirable color and/or sheen or gloss.
It has thus also been an objective of this invention to provide a mulch system from ground, waste rubber and a binder, and means for controlling the appearance of the cured mulch mat to provide desirable color and aesthetics.
To this end, in making pads of the preferred embodiment, a binder comprising urethane is used, and is mixed together with pigment to provide a desirable color. This is preferably mixed with a catalyst to promote curing and the ground rubber and fibers are mixed therein. This mixture is then molded into a desired shape and a diatomaceous earth or silica is sprinkled over the uncured mixture to produce a desirable anti-gloss effect in the cured pad so produced.
The mulching system provided by the invention provides numerous advantages. When used around a tree, it prevents grass and weed growth around the trunk, thus making it unnecessary to trim or mow closely thereto. At the same time, it provides a relatively inexpensive, natural appearing mulch system with little, if any, continuing maintenance needed. At the same time, the mulch system is porous, transmitting moisture and air to the root system, both facilitating its nourishment and insulating it.
While the pad transmits air and moisture, its voids, between the bound rubber granules and fibers, do not operate as capillaries, pulling water away from the root system. Instead, the pad insulates the root system and retains water and-condensate beneath the pad for benefit of the root system.
It will also be appreciated that the pad provides erosion protection for the underlying soil and root system. For example, even a high velocity stream of water directed against the pad will, by the time the water travels through the pad, be broken down into low velocity droplets. This serves to disperse fluid energy, and prevents soil erosion while the pad does not mechanically degenerate and remains in place, reducing maintenance concerns. Not only does the pad transform high velocity water streams into a plurality of dispersed water droplets, but it will be appreciated that the pad disperses the water laterally through the pad for greater overall moisture coverage.
Accordingly, pads or mats of the composition according to the invention can be used over ground to prevent erosion, such as on hillsides, under downspouts, in walk areas, steps and the like.